title: Prognostic value of kallikrein-related peptidase 6 protein expression levels in advanced ovarian cancer evaluated by automated quantitative analysis (AQUA).
abstract: Kallikrein-related peptidases, a subgroup of the serine protease enzyme family, are considered important prognostic biomarkers in cancer. In the present study, we sought to determine the prognostic value of kallikrein-related peptidase 6 (KLK6) in ovarian cancer using a novel method of compartmentalized in situ protein analysis. A tissue array composed of 150 advanced stage ovarian cancers, uniformly treated with surgical debulking followed by platinum-paclitaxel combination chemotherapy, was constructed. For evaluation of KLK6 protein expression, we used an immunofluorescence-based method of automated in situ quantitative measurement of protein analysis (AQUA). Mean follow-up time of the cohort was 34.35 months. One hundred and thirty-five of 150 cases had sufficient tissue for AQUA analysis. In univariate survival analysis, low tumor KLK6 expression was associated with better outcome for overall survival over 3 years (P = 0.019). There was no association between tumor KLK6 expression and progression-free survival (P = 0.128). In multivariate survival analysis, adjusting for well-characterized prognostic variables, low tumor KLK6 expression level was one of the most significant predictor variable for overall survival (95% confidence interval, 1.19-3.50; P = 0.009). High tumor KLK6 protein expression is associated with inferior patient outcome in ovarian cancer. KLK6 may represent a promising disease biomarker and therapeutic target in ovarian cancer.
authors.affiliation: Departments of Medical Oncology, Yale Cancer Centre, New Haven, Connecticut 06520-8023, USA.
authors.forename: Panteleimon
authors.initials: P
authors.lastname: Kountourakis
authors.forename: Amanda
authors.initials: A
authors.lastname: Psyrri
authors.forename: Andreas
authors.initials: A
authors.lastname: Scorilas
authors.forename: Robert
authors.initials: R
authors.lastname: Camp
authors.forename: Sonia
authors.initials: S
authors.lastname: Markakis
authors.forename: Diane
authors.initials: D
authors.lastname: Kowalski
authors.forename: Eleftherios P
authors.initials: EP
authors.lastname: Diamandis
authors.forename: Meletios A
authors.initials: MA
authors.lastname: Dimopoulos
mesh_terms: D015331:Cohort Studies; D001330:Electronic Data Processing; D005260:Female; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006801:Humans; D007610:Kallikreins / Q000235:genetics*; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D015996:Survival Rate; D046888:Tissue Array Analysis
chemical_list: C103551:KLK6 protein, human; D007610:Kallikreins